Isolation, characterization and screening for anti-microbial properties of heterotrophic bacteria from Haliclona koremella and its ambient seawater

A total of 87 heterotrophic bacteria isolated from Haliclona koremella and its ambient seawater were characterized in terms of their colonial, microscopic and biochemical characteristics. In terms of the colonial morphology, most colonies exhibited white or cream pigmentation, rounded shape, unelevated and mucoid colonies with the diameter of the colony ranging from 0.1 mm. to 15 mm. In terms of the microscopic morphology, 50.57 of the total number of isolates were Gram positive, 44.83 were Gram negative and 4.60 were Gram variable. Cocci made up 60.92 of the total number of isolates, 34.48 were rods and 4.60 were coccobacilli. The biochemical tests done were the following: methyl red test, Voges-Proskauer test (MR-VP), Simmons-Citrate utilization test, urease test, catalase reaction and coagulase test. The antibiotic susceptibility pattern of the isolates against selected antibiotics made use of the following: nalidixic acid, tetracycline, penicillin, erythromycin and chloramphenicol. The isolates were also screened for the presence of anti-microbial properties against three test microorganisms, namely, Staphylococcus aureus, Escherichia coli and Candida albicans. Two isolates, S29 and S50 had inhibitory effect on the growth of S. aureus.